Asterix category 008 - Monoradar Derived Weather Information

category: 008

edition: 1.2

date: 2014-08-24

Preamble

Surveillance data exchange.

Description of standard data items

I008/000 - Message Type

Definition: This Data Item allows for a more convenient handling of the messages at the receiver side by further defining the type of transaction.

Structure:

• 8 bits [........]

• values:

  1: Polar vector
  2: Cartesian vector of start point/length
  3: Contour record
  4: Cartesian start point and end point vector
  254: SOP message
  255: EOP message

I008/010 - Data Source Identifier

Definition: Identification of the radar station from which the data are received.

Structure:

I008/010/SAC - System Area Code

• 8 bits [........]
• raw value

I008/010/SIC - System Identification Code

• 8 bits [........]
• raw value

Note:

The defined SACs are on the EUROCONTROL ASTERIX website (www.eurocontrol.int/asterix)

I008/020 - Vector Qualifier

Definition: Precipitation intensity level, shading orientation of the vectors representing the precipitation area and coordinate system used.

Structure:

Extended item.

I008/020/ORG

• 1 bit [.]

• values:

  0: Local Coordinates
  1: System Coordinates

I008/020/I - Intensity Level

• 3 bits [...]
• unsigned integer

I008/020/S - Shading Orientation with Respect to North

• 3 bits [...]

• values:

  0: 0°
  1: 22.5°
  2: 45°
  3: 67.5°
  4: 90°
  5: 112.5°
  6: 135°
  7: 157.5°

(FX)

• extension bit

  0: End of data item
  1: Extension into next extent

I008/020/(spare)

• 5 bits [.....]

I008/020/TST

• 1 bit [.]

• values:

  0: Default
  1: Test vector

I008/020/ER

• 1 bit [.]

• values:

  0: Default
  1: Error condition encountered

(FX)

• extension bit

  0: End of data item
  1: Extension into next extent

Note:

For polar vectors bits-4/2 are meaningless and are set to zero.

I008/034 - Sequence of Polar Vectors in SPF Notation

Definition: Sequence of weather vectors in local polar coordinates.

Structure:

Repetitive item, repetition factor 8 bits.

I008/034/STR - Start Range

• 8 bits [........]

• unsigned quantity

• unit: “(NM)”

• LSB = 1/2⁷ (NM)  ≈ 7.81e − 3 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/034/ENDR - End Range

• 8 bits [........]

• unsigned quantity

• unit: “(NM)”

• LSB = 1/2⁷ (NM)  ≈ 7.81e − 3 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/034/AZ - Azimuth

• 16 bits [................]
• unsigned quantity
• unit: “°”
• LSB = 360/2¹⁶ °  ≈ 5.49e − 3 °

Note:

f is a parameter of the SOP message.

I008/036 - Sequence of Cartesian Vectors in SPF Notation

Definition: Sequence of weather vectors, in the representation start point/length, in local or in system cartesian coordinates.

Structure:

Repetitive item, repetition factor 8 bits.

I008/036/X - X-Component

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/036/Y - Y-Component

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/036/LENGTH - Length

• 8 bits [........]

• unsigned quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

Note:

1. LSB of [X, Y, L] is calculated as 2^−6 + F.
2. F is a parameter of the SOP message.
3. Negative values are expressed in 2’s complement form, bit-24 and bit-16 are set to 0 for positive values and 1 for negative values.

I008/038 - Sequence of Weather Vectors in SPF Notation

Definition: Sequence of weather vectors, in the representation start point/ end point, in local or in system cartesian coordinates.

Structure:

Repetitive item, repetition factor 8 bits.

I008/038/X1 - X1-Component

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/038/Y1 - Y1-Component

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/038/X2 - X2-Component

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/038/Y2 - Y2-Component

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

Note:

1. LSB of [X1, Y1, X2, Y2] is calculated as 2^−6 + f.
2. f is a parameter of the SOP message.
3. Negative values are expressed in 2’s complement form, bits-32, 24, 16 and 8 are set to 0 for positive values and 1 for negative values.

I008/040 - Contour Identifier

Definition: Contour serial number together with the precipitation intensity levels and the coordinates system used.

Structure:

I008/040/ORG

• 1 bit [.]

• values:

  0: Local Coordinates
  1: System Coordinates

I008/040/I - Intensity Level

• 3 bits [...]
• raw value

I008/040/(spare)

• 2 bits [..]

I008/040/FSTLST

• 2 bits [..]

• values:

  0: Intermediate record of a contour
  1: Last record of a contour of at least two records
  2: First record of a contour of at least two records
  3: First and only record, fully defining a contour

I008/040/CSN - Contour Serial Number

• 8 bits [........]
• raw value

Note:

The Contour Serial Number provides an unambiguous identification for each contour record. Within one update cycle, a serial number shall never be assigned twice.

I008/050 - Sequence of Contour Points in SPF Notation

Definition: Cartesian coordinates of a variable number of points defining a contour.

Structure:

Repetitive item, repetition factor 8 bits.

I008/050/X1

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

I008/050/Y1

• 8 bits [........]

• signed quantity

• unit: “(NM)”

• LSB = 1/2⁶ (NM)  ≈ 1.56e − 2 (NM)

  remark

  Adjust with scaling factor ‘100/F’

Note:

1. LSB of [X1, Y1] is calculated as 2^−6 + f.
2. f is a parameter of the SOP message.
3. Negative values are expressed in 2’s complement form, bit-16 and bit-8 shall be set to 0 for positive values and 1 for negative values.

I008/090 - Time of Day

Definition: Absolute time stamping expressed as Coordinated Universal Time (UTC) time.

Structure:

• 24 bits [........................]
• unsigned quantity
• unit: “s”
• LSB = 1/2⁷ s  ≈ 7.81e − 3 s

Notes:

1. The time of day value is reset to zero each day at midnight.
2. For time management in radar transmission applications, refer to Part 1, paragraph 5.4 [Ref. 1].

I008/100 - Processing Status

Definition: Information concerning the scaling factor currently applied, current reduction step in use, etc.

Structure:

Extended item.

I008/100/F - Scaling Factor

• 5 bits [.....]
• signed integer

I008/100/R - Current Reduction Stage in Use

• 3 bits [...]
• raw value

I008/100/Q - Processing Parameters

• 15 bits [...............]
• raw value

(FX)

• extension bit

  0: End of data item
  1: Extension into next extent

Note:

F: Scaling factor, negative values are represented in 2’s complement form, bit-24 is set to 0 for positive values and 1 for negative values. R: Current reduction stage in use. Normal operation is indicated by a value of zero. The actual bit signification is application dependent. Q: Processing parameters. The actual bit signification isapplication dependent.

I008/110 - Station Configuration Status

Definition: Information concerning the use and status of some vital hardware components of a radar system .

Structure:

Repetitive item with FX extension

• 7 bits [.......]
• raw value

Note:

Due to the diversity in hardware design and requirements of present and future radar stations, it is felt impractical to attempt to define individual bits.

I008/120 - Total Number of Items Constituting One Weather Picture

Definition: Total number of vectors, respectively contour points, constituting the total weather image, provided with the EOP message.

Structure:

• 16 bits [................]
• unsigned integer

I008/SP - Special Purpose Field

Definition: Special Purpose Field

Structure:

Explicit item (SP)

I008/RFS - Random Field Sequencing

Definition: Random Field Sequencing

Structure:

Rfs

User Application Profile for Category 008

• 1. I008/010 - Data Source Identifier
• 2. I008/000 - Message Type
• 3. I008/020 - Vector Qualifier
• 4. I008/036 - Sequence of Cartesian Vectors in SPF Notation
• 5. I008/034 - Sequence of Polar Vectors in SPF Notation
• 6. I008/040 - Contour Identifier
• 7. I008/050 - Sequence of Contour Points in SPF Notation
• (FX) - Field extension indicator
• 8. I008/090 - Time of Day
• 9. I008/100 - Processing Status
• 10. I008/110 - Station Configuration Status
• 11. I008/120 - Total Number of Items Constituting One Weather Picture
• 12. I008/038 - Sequence of Weather Vectors in SPF Notation
• 13. I008/SP - Special Purpose Field
• 14. I008/RFS - Random Field Sequencing
• (FX) - Field extension indicator